The present invention pertains to an optical device for use under significantly varying ambient pressure. The invention may be used in the context of a periscope or an optronics mast.
In conventional periscopes or optronics masts for submarines, the panes, through which the light is incident, and the corresponding seal of the housing need to withstand the ambient pressure in any situation. Due to the high ambient pressures occurring in the submerged state, the expenditure for the seal is comparatively high and the panes themselves need to be realized in a comparatively thick and consequently costly fashion in order to withstand these high pressures. This not only results in a comparatively expensive, heavy and large arrangement, but the required thickness of the panes also has negative effects on the optical performance of the entire system due to the associated absorption and the aberrations resulting thereof.
On the other hand, to deal with the above problem of high pressures occurring in the submersed state, it is known from DE 78 00 786 U1 to completely retract the periscope or optronics mast into a receptacle integrated into the submarine's shell. The receptacle is then sealed using a cover at the free end of the periscope or optronics mast. Anyway, this has the disadvantage that the periscope or optronics mast either must always be completely retracted at comparatively low submersion levels with low pressure levels or the components will have to be designed for higher pressure levels.